PubMed Health⌕ Search

Biomedical subjects

G Royer

Publications and source records attributed to G Royer.

At least 19 recordsLinked to original sources
PubMed2006

Prenatal diagnosis of myopathy, encephalopathy, lactic acidosis, and stroke-like syndrome: contribution to understanding mitochondrial DNA segregation during human embryofetal development.

INTRODUCTION: Myopathy, encephalopathy, lactic acidosis, and stroke-like (MELAS) syndrome, a maternally inherited disorder that is among the most common mitochondrial DNA (mtDNA) diseases, is usually associated with the m.3242A>G mutation of the mitochondrial tRNA(leu) gene. Very few data are available with respect to prenatal diagnosis of this serious disease. The rate of mutant versus wild-type mtDNA (heteroplasmy) in fetal DNA is indeed considered to be a poor indicator of postnatal outcome. MATERIALS AND METHODS: Taking advantage of a novel semi-quantitative polymerase chain reaction test for m.3243A>G mutant load assessment, we carried out nine prenatal diagnoses in five unrelated women, using two different fetal tissues (chorionic villi v amniocytes) sampled at two or three different stages of pregnancy. RESULTS: Two of the five women, although not carrying m.3243A>G in blood or extra-blood tissues, were, however, considered at risk for transmission of the mutation, as they were closely related to MELAS-affected individuals. The absence of 3243A>G in the blood of first degree relatives was associated with no mutated mtDNA in the cardiovascular system (CVS) or amniocytes, and their three children are healthy, with a follow-up of 3 months-3 years. Among the six fetuses from the three carrier women, three were shown to be homoplasmic (0% mutant load), the remaining three being heteroplasmic, with a mutant load ranging from 23% to 63%. The fetal mutant load was fairly stable at two or three different stages of pregnancy in CVS and amniocytes. Although pregnancy was terminated in the case of the fetus with a 63% mutant load, all other children are healthy with a follow-up of 3 months-6 years. CONCLUSION: These data suggest that a prenatal diagnosis for MELAS syndrome might be helpful for at-risk families.

Acidosis, Lactic↗
PubMed2001

MECP2 mutation in non-fatal, non-progressive encephalopathy in a male.

To study the clinical overlap between Rett (RTT) and Angelman syndromes (AS), we screened the MECP2 gene in a cohort of 78 patients diagnosed as possible AS but who showed a normal methylation pattern at the UBE3A locus. MECP2 missense (R106W, G428S), nonsense (R255X, R270X), and frameshift mutations (803 delG) were identified in 6/78 patients including 4/6 female cases consistent with RTT, one female case with progressive encephalopathy of neonatal onset, and one isolated male case with non-fatal, non-progressive encephalopathy of neonatal onset. This study shows that MECP2 mutations can account for a broad spectrum of clinical presentations and raises the difficult issue of the screening of the MECP2 gene in severe encephalopathy in both males and females.

Angelman Syndrome↗
PubMed1993

Prenatal exclusion of X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence using closely linked DNA markers.

X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence (H-SAS, MIM number 307,000) is a rare genetic disorder characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, mental retardation, and cerebral malformations. This regularly lethal condition is usually diagnosed at birth or prenatally by ultrasound, but hydrocephalus may be moderate or even undetectable on fetal ultrasound examination. Moreover, since heterozygous women are asymptomatic, carrier detection is at present impossible before the birth of an affected son. Therefore, mapping the H-SAS locus to distal Xq (Xq28) was of primary importance for genetic counselling and prenatal diagnosis. Here, we report prenatal exclusion of H-SAS with a probability of 97.6 per cent in two male fetuses with a 50 per cent a priori risk of being affected using closely linked Xq28 DNA markers.

Cerebral Aqueduct↗
PubMed1992

The gene for X-linked hydrocephalus maps to Xq28, distal to DXS52.

We report the study of five independent X-linked hydrocephalus (HSAS1) families with polymorphic DNA markers of the Xq28 region. A total of 58 individuals, including 7 living affected males and 22 obligate carriers, have been studied. Maximum lod score was 7.21 at theta = 2.40% for DXS52 (St14-1). A single recombination event was observed between this marker and the HSAS1 locus. Other markers studied were DXS296 (Z = 2.02 at theta = 2.5%), DXS304 (Z = 4.37 at theta = 7.8%), DXS74 (Z = 3.50 at theta = 0%), DXS15 (Z = 1.96 at theta = 5.7%), DXS134 (Z = 3.31 at theta = 0%), and F8C (Z = 5.79 at theta = 0%). These data confirm the localization of the HSAS1 gene to Xq28 and provide evidence for genetic homogeneity of this syndrome. In addition, examination of two obligate recombinant meioses along with multipoint linkage analysis supports the distal localization of the HSAS1 locus with respect to the DXS52 cluster. These observations are of potential interest for future studies aimed at HSAS1 gene characterization.

Chromosome Mapping↗
PubMed1992

The gene for hereditary multiple exostoses does not map to the Langer-Giedion region (8q23-q24).

Hereditary multiple exostoses is a dominantly inherited skeletal disorder which alters enchondral bone during growth and is characterised by exostoses of the juxta-epiphyseal regions. Using polymorphic DNA probes, we have been able to exclude the disease gene from close proximity to the 8q24.1 region where a dominant syndrome with multiple exostoses, the trichorhinophalangeal syndrome type II (TRP II, Langer-Giedion syndrome, MIM 15025), has been previously localised (pairwise linkage Z = -8.96 at theta = 0 with probe L48 at locus D8S51). Multipoint linkage analysis using probes L48, L24, and L1 consistently excluded the HME gene from a large area of the distal long arm of chromosome 8, spanning the smallest region of overlap assigned to the TRP II gene. These studies support the clinical view that HME and TRP II are distinct entities.

Chromosomes, Human, Pair 8↗
PubMed1990

Clinical pharmacology of predisintegrated ibuprofen 800 mg tablets: an endoscopic and pharmacokinetic study.

Thirty-five healthy adults were randomized to receive either: (1) ibuprofen 800 mg tablets; (2) ibuprofen 800 mg aqueous suspension; (3) ibuprofen 800 mg orange juice suspension; or (3) 325 mg aspirin tablets. All treatments were tid for 7 days. Pharmacokinetic sampling was conducted on days 1, 4 and 8. Gastroduodenoscopy was performed on days 1 and 8. Side effects and safety laboratory tests were monitored throughout the study. On day 8 the aspirin group showed significantly more gastric irritation than all of the ibuprofen groups (P less than .005). Both ibuprofen suspension groups showed more gastric irritation than the ibuprofen tablet group (P less than .1). The duodenal scores did not differ among the treatment groups. The aspirin group experienced a higher rate of tinnitus and abdominal pain. The rate and extent of absorption of the ibuprofen suspensions were significantly less than that of the tablets. These data suggest that the taking of ibuprofen as an extemporaneous suspension is therapeutically inferior to ibuprofen tablets and therefore should be discouraged.

Adult↗
PubMed1990

Multiple-dose safety study of ibuprofen/codeine and aspirin/codeine combinations.

This multiple-dose, double-blind, placebo-controlled, randomized, normal volunteer study compared formulations of ibuprofen/codeine and aspirin/codeine for systemic safety. Vital signs, hematologic, biochemical and urinary parameters, side effects, mood and mental alertness, were monitored. The placebo group had less gastrointestinal side effects and more frequent stools than the active treatment groups. There was statistical evidence for greater adverse effects of aspirin/codeine on mood and mental alertness in comparison to ibuprofen/codeine and placebo. Ibuprofen/codeine had a more favorable adverse effect profile than aspirin/codeine. A mild respiratory and cardiac depressant effect attributable to codeine was evident in all active treatment groups after 7 days of frequent therapy. More work needs to be done to elucidate the factors regulating the development of tolerance to the respiratory and cardiovascular depressant effects of opiates in general, and for codeine in particular.

Adult↗
PubMed1985

Complications of heparin administration in normal individuals.

The incidence, severity, and pathogenic mechanism of heparin-associated thrombocytopenia with both bovine and porcine heparin administration were studied in forty normal males randomized to one of four treatment groups: beef lung heparin #1, beef lung heparin #2, porcine gut heparin, and saline control. All of the subjects receiving heparin developed a reversible increase in serum transaminases (SGOT, SGPT). However, other measurements of liver function were normal. Thirty-three percent of these heparinized normals had decreased platelet counts. The incidence of platelet count decrease was similar for both bovine and porcine heparins, but 4 of the 20 normals receiving bovine heparin had platelet counts less than 150,000/microliters. Immune pathogenesis was investigated by analyzing plasma from the volunteers for both platelet antibody and immune complexes. None of the men had increased platelet-associated IgG. Among the ten subjects with decreased platelet counts, IgG immune complexes were detected in three and C1q in seven. The heparin-associated thrombocytopenia appears not to be mediated by a platelet antibody. More probably it reflects a direct effect of the heparin on platelets.

Adult↗
PubMed1975

Ineffectiveness of subcutaneous cytosine arabinoside in localized herpes zoster.

Cytosine arabinoside (cytarabine) was evaluated in a randomized double-blind controlled study for the treatment of localized herpes zoster. Cytarabine was administered subcutaneously in a dose of 50 mg/m-2 body surface area once daily for 4 days, always within 14 days of onset of the first symptom and usually within 7 days. Thirty patients given cytarabine and 30 patients given placebo were well matched with respect to age, sex, and length and severity of presenting rash and pain as well as underlying disease. There was no difference in the rate of disappearance of pain or rash in either treatment group. More patients given cytarabine than patients given placebo had minimal pain and significantly more cytarabine-treated patients had persistence of neurological symptoms at 6 months' follow-up. Acute side effects, though mild, were significantly increased in the cytarabine-treated patients especially with respect to nausea and vomiting and decrease in platelet count. Cytarabine administered in this dose subcutaneously had no beneficial effect and was associated with mild side effects and persistence of neurological symptoms.

Adult↗